Gut enzymes could hold key to producing universal blood: UBC study

Now researchers at the University of British Columbia have identified a new, more powerful group of enzymes that can turn any type of blood into the universally usable type O-expanding the pool of potential blood donors and making blood matching safer and easier.

If a person receives a blood transfusion of a blood type that's not their own, their immune system will attack and kill the donated blood cells.

Whereas type A or B blood can only receive transfusions from (or make donations to) others with the same blood type, medical professionals can use type O blood with any of the three other major blood types: A, B, or O. Type AB, the other of the four major blood types, works in reverse; it can receive blood from any other type but only donate to others who are type AB.

With aid from the Centre for Blood Research at the University of British Columbia, the researchers are applying for a patent on their new enzyme research and are testing more blood samples before beginning clinical trials. Instead of culturing microbe after microbe in a painstaking process, the research team simply extracted DNA from all the microorganisms found in the human gut.

Scientists claim they may have identified gut bacteria that could convert blood types A and B into type O.

But O-blood, specifically O-negative, are the universal donors because they lack A and B antigens. Some of these sugars have the same structure as the antigens on A- and B-type blood.

They then used a specific bacterium that helped them to determine which types of DNA could code enzymes to remove certain sugars, including blood specific antigens that determine blood group compatibility. "There are further tests we need to do to make sure that in the process we've not inadvertently changed anything else on the red blood cell surface which could be deleterious to its function".

The researchers presented their results this week at the 256th National Meeting & Exposition of the American Chemical Society. "However, these new enzymes can do the job 30 times better".

Researchers have long sought a method to remove antigens from A, B and AB blood to convert it into type O, but have not been able to find a reliable, feasible method.

"The next step is very much all about safety", he said.

Because of type-O negative's universality, it is useful in emergency surgery, for instance, when there isn't time to test for a patient's blood type. "That's really important because we don't want to modify the red blood cell in some way that might compromise it", Withers said.